Hi, I`m sure that in digital scope you have the option to set a specific level of tension in the trigger, that capture a screen from that moment (single capture ore something like that), but I don`t remember if exits the same in a analog one, take a look at the trigger options.

Pretty tricky to do if your camera doesn't have a "B" setting (open shutter). You have access to a video camera, may I suggest another vid clip? Grab the frame that shows the pulse. Nice project btw. You have done the proof of concept, how about looking at any criticisms and see if there's anything you could work into v2.0?

Now I'm working at my magnetic stirrer V2.0, but in the near future I will also make the pulse magnetizer v2.0.I will think of making a new video. By the way, the photos were taken with a smartphone camera.Thank you.

Yes I saw the stirrer, great work there too, so I look forward to V2.0.

Another covering idea for the magnet would be to smother it in bathroom sealant silicone - probably even more inert than hot glue? You could make a mould out of a biro tube or similar, pump it full of silicone, insert magnet, top up with more silicone and when set gently break out of the tube and trim.

" ...photos were taken with a smartphone camera."

Ah but if your video was taken using your smartphone too, then it's even easier to grab an image that captures that pulse spot-on. Just an idea if you need to capture a transient event. : )